Attack vulnerability of scale-free networks due to cascading failures

In this paper, adopting the initial load of a node i to be ak(i)(alpha) with k(i) being the degree of the node i, we propose a cascading model based on a load local redistribution rule and examine cascading failures on the typical network, i.e., the BA network with the scale-free property. We find that the BA scale-free network reaches the strongest robustness level in the case of alpha = 1 and the robustness of the network has a positive correlation with the average degree < k >, where the robustness is quantified by a transition from normal state to collapse. in addition, we further discuss the effects of two different attacks for the robustness against cascading failures on our cascading model and find an interesting result, i.e., the effects of two different attacks, strongly depending to the value alpha. These results may be very helpful for real-life networks to avoid cascading-failure-induced disasters. (C) 2008 Elsevier B.V. All rights reserved.